U.N. warns of $15-billion funding gap on humanitarian aid due to war or natural disasters

DAVOS, Switzerland—The global refugee crisis is stretching the budgets of governments and international organizations, prompting a search for novel ways to raise money from private investors or special levies on goods such as fuel, plane tickets or even concerts.

With 125 million people across the globe now depending on humanitarian aid due to war or natural disasters—a 12-fold increase since the start of the century—there is a $15 billion funding gap, according to a United Nations report released over the weekend. Filling...